Bacterial Vaginosis (BV) is a clinical syndrome characterised by malodorous discharge. Bacterial Vaginosis is the most common type of vaginal infection in women of reproductive age, accounting for 45% of all vulvovaginal infections. Moreover, it has been related to a variety of upper genital tract infections and obstetrical complications. These include pelvic inflammatory disease (PID), post-Caesarean endometritis, posthysterectomy pelvic infection, chorioamnionitis, premature rupture of membranes (PROM) and preterm labour and delivery. The prevention of these infections for a woman and her child is an important issue in women's health (1).
Fifteen percent of gynaecologic patients and 10-30 percent of pregnant women have BV, whilst up to 60 percent of women visiting a clinic for sexually transmitted diseases are estimated to suffer from BV (1).
Bacterial Vaginosis has been associated with non-white race, sexual activity and the intra-uterine device, but no precise studies are available. There are indications of sexual transmission of the disease, but other routes are also indicated.
The normal vaginal flora is dominated by lactobacilli which account for 95 percent of the bacteria present in the vagina, with other facultative and anaerobic bacteria present in only small numbers. Bacterial Vaginosis represents a complex change in the vaginal ecosystem characterised by a reduction in the prevalence and concentration of lactobacilli and an increase in the prevalence and concentration of Gardnerella vaginalis, anaerobic gram-negative rods, and Mycoplasma hominis. In BV, a flora consisting primarily of benign lactobacilli is replaced by a flora consisting of high concentrations of potentially virulent bacteria. Lactobacilli maintain the acid pH in the vagina by producing lactic acid which maintains a low pH of normally less than 4.5. Low pH directly inhibits the growth of anaerobic organisms. Hydrogen peroxide-producing lactobacilli also appear to play a role in limiting Gardnerella and the anaerobic flora of the vagina (1). Moreover the especially virulent Prevotella and Porphyromonas species are present in particular high numbers in patients with BV (1).
When affected women are symptomatic, they complain predominantly of vaginal odour. The odour is described as fishy. Patients often refer to embarrassing vaginal odour especially after intercourse. About 90 percent of patients also notice a mild to moderate discharge. Pain symptoms are rare because the infection is not linked to inflammation of the tissue. Patients with BV may not display the symptoms that would normally alert their physicians to the infection. In fact, nearly half of the patients with BV do not complain of excess or malodorous vaginal discharge.
The diagnosis requires three of the following signs to be present:
1. A homogenous, white or grey, noninflammatory discharge that adheres to the vaginal wall.
2. The presence of clue cells (>20% of the epithelial cells in 400× magnification) on microscopic examination of fresh smears.
3. The pH of vaginal secretions greater than or equals 4.7.
4. A fishy odour of vaginal discharge before or after adding of 10% KOH.
Culture of Gardnerella vaginalis is not recommended as a diagnostic tool, as it is not specific.
A study showed that patients with BV had a 5.1-fold higher risk of post-partum endometritis following Caesarean section than did patients with a lactobacilli-dominant flora.
Patients with BV have a four times higher rate of vaginal-cuff cellulitis following abdominal hysterectomy than patients with a lactobacillus-dominant flora (1).
The rate of post-abortion pelvic inflammatory disease was three times less in patients treated with a BV-effective antibiotic related to placebo-treated patients. Prematurity occurs 1.9 times more commonly, and premature rupture of membranes occurs 3.5 times more commonly in women with BV than in those without BV. BV bacteria are frequently isolated from amniotic fluid and could play a major role in premature delivery (1).
The established medicine offers the treatment of either of two antibiotics, clindamycin or metronidazole, either topically or by the oral route.
Metronidazole as a 7-day treatment has an 80-90% cure rate after 1 month. Side effects are nausea, abdominal cramps and a metallic taste. The patient must refrain from alcohol intake, as it may produce antabuse effects. It is not recommended in the first trimester of pregnancy.
Clindamycin as a 7-day treatment has equal effects as metronidazole, and its side effects are less, though diarrhoea is possible. Concerns about Clostridium difficile colitis have prevented the widespread use.
Topical application through vaginal preparations has minimised side effects; however, this approach is more expensive.
The cure rate is high but a significant proportion of women suffer relapses and recurrences. There is some evidence that residual biochemical and microbiological abnormalities persist in these women (2).
Different alternative measures have been advised (live yoghurt bacteria, Lactobacillus acidophilus preparations, acetic acid flushes (several hits on the Internet). Studies of live yoghurt or Lactobacillus acidophilus have not demonstrated benefits (3).
In U.S. Pat. No. 6,440,949 a method for increasing the acidity in vagina is suggested. The method suggests to administer an amount of 2.5% to 17% (w/v) of one or more saccharides in an acidic medicament. The patent tests different concentrations of saccharides, but none of the concentrations shows a significant decrease in pH, and furthermore, none of the concentrations shows elimination of the odour causing bacteria, the Gram negative bacteria (G-b). In U.S. Pat. No. 6,440,949, no relation is shown between the concentration of the saccharide and the results obtained.